应用抗-HBc单克隆抗体研究乙型肝炎核心抗原的抗原位点  

ANTIGENIC SITES OF HBcAg DETERMINED BY MONOCLONAL ANTIBODIES

作　　者：詹美云[1] 汤少华[1] 张文英[1] 田瑞光[1] 张满仓 刘崇柏[1] 

机构地区：[1]中国预防医学科学院病毒学研究所

出　　处：《病毒学报》1990年第2期140-144,共5页Chinese Journal of Virology

基　　金：国家"七五"攻关课题

摘　　要：应用基因工程表达的乙型肝炎核心抗原(HBcAg)免疫Balb/c小鼠,取该鼠的脾细胞与小鼠骨髓瘤细胞融合,获得8株能稳定分泌高滴度抗HBcAg抗体的杂交瘤细胞株.用其中7株(4A4、4B5、3H6、3A5、1G8、1D3、5G10)与HBcAg亲和性相近的单克隆抗体(McAb)首次证明,在HBcAg上存在3个不同的抗原位点,并分别命名为α、β和γ. α抗原位点:能诱生中和及免疫沉淀抗体,在体外能中和HBcAg的抗原活性,能与HBc-Ag产生免疫沉淀线.如3H6、4A4、4B5、3A5等单克隆抗体. β抗原位点:不能诱生中和及免疫沉淀抗体,但此种单克隆抗体与4A4或4B5混合后即可与HBcAg产生免疫沉淀线.如1G8、1D3 McAbs. γ抗原位点:能诱生免疫沉淀抗体,但不能诱生中和抗体.如5G10McAb. 抗相同抗原位点的单克隆抗体之间可产生有意义的互相竞争抑制,而抗不同抗原位点的单克隆抗体之间则无,或很少有竞争抑制.对有关问题进行了讨论.Balb/c mice were immunized with purified HBcAg expressed in E.coli, Eight hybridomas secreting antibodies to HBcAg were established.The ELISA titers of ascitic fluid McAbs were 105-6×105. Three of them were IgG1,3 were IgG2a,others were IgM. 7 out of 8 McAbs showing a strong affinity to HBcAg were used to study the determinants of HBcAg by the methods of immunodiffusion and cross-competition between HRP-labelled and unlabelled McAbs when they were mixed and reacted with HBcAg. The results showed that 5 of them can precipitate with HBcAg but 2 others can not. If these latter McAbs were mixed with precipiting 4A4 or 4B5 McAbs, however two precipitation lines were formed. These results suggest that at least two antigenic sites exist on HBcAg. Each of the HRP-labelled McAbs ( 3H6, 4B5, lG8 ) was mixed with each of the unlabelled McAbs (3H6, 4A4, 4B5, 3A5 , lG8, lD3, 5G10)to test their cross-competition in ELISA. The results showed cross-competition between 3H6,4A4, 465 and 3A5 and between 1Gs, 1D3. But McAb 5G10 had no significant crosi-competition with any of the other 6 McAbs. According to these results the antigenic sites on HBcAg were classified into three groups and were named α, β,γ . McAbs against the a site of HBcAg are neutralizing and precipitating antibodies such as 4A4, 4B5, 3H6 and 3A5. McAbs against the 3 site of HBcAg such as lG8 and lD3,are non-neutralizing and non-precipitating antibodies, but if combined with 4A4 or 4B5 can form two precipitation lines. McAb against the r site of HBcAg such as 5GlO is precipitating but does not cross-compete with other McAbs.We discovered for first time that there are three antigenic sites on HBcAg. It is important for the delineation of the antigenic structure of HBcAg and it is useful in the development of diagnostic reagents for detecting HBcAg and anti-HBc.

关 键 词：乙型肝炎 核心抗原 抗原位点 

分 类 号：R512.620.3[医药卫生—内科学]